What better way to portray robots and androids on stage than by having actual robots and androids perform their own parts? Such is the thinking behind the Japanese Robot Theater Project. The troupe's latest productions, "Sayonara" and "I, Worker," feature robots that interact with live performers right on stage. And not surprisingly, they never miss their cues.

In addition to moving and interacting with the actors, some of the bots employ artificial voices, but the androids were given a real human voice in order to ensure realism — to cross the so-called "uncanny valley."

The robotic stars included a "Gemnoid F" android that appeared as a lifelike Japanese woman, as well as two "Robovie R3" models that looked more like oversized robot toys. The machines performed their prerecorded scripts alongside human actors from the Seinendan Theater Company.

"Sayonara" featured the Gemnoid F android acting as a poetry-reciting companion to a blonde girl suffering from a terminal condition. The android's humanlike appearance included blinking eyes, mouth movements and several facial expressions.

Despite Gemnoid F's acting limitations, audiences often interpreted the android's performance as conveying a much broader emotional range, said Bryerly Long, a multilingual actress with the Seinendan Theater Company who both supplied the recorded voice for the android and acted in the role of the dying blonde girl. She made her observation during a Q&A session following the two short plays.

An extended scene for "Sayonara" included a melancholy nod to the Fukushima Daiichi nuclear disaster that followed in the wake of the 2011 Japanese earthquake and tsunami. Hirata, the playwright, took inspiration for the scene from news reports describing how robots could help in the radioactive zone surrounding the nuclear plant meltdown.

Androids aren't a threat to real actors just quite yet, but Oriza Hirata, the show's playwright and director, predicts that they will be in the next few decades.